1. Field of the Invention
This disclosure relates generally to lubrication systems and, more particularly, to an air compressor lubrication system for use on a railway vehicle.
2. Description of Related Art
Lubrication systems for railway vehicle air compressors are well known and have remained virtually unchanged since the 1940s. Despite some advances in maintenance and inspection methods to ensure trouble-free operation of the lubrication systems, easy operator access to air compressor components for maintenance or to address failure of system components has been a continuing problem.
Currently known lubrication systems utilized in many air compressors rely upon moving oil to wear areas of the air compressor using an oil distribution ring mounted on and circumscribed about the air compressor crankshaft. Such distribution rings are fed oil through delivery means such as a flexible transfer line to an inlet on the distribution ring. An example of one such configuration is described in U.S. Pat. No. 5,183,134 to Kuc, incorporated herein by reference in its entirety. In operation, the combination of a flexible transfer line and vibrations caused by oscillating and reciprocating components of the air compressor result in undesired movement (e.g., rotation) of the distribution ring on the crankshaft and subsequent fatigue failure of the flexible transfer line and other components directly and indirectly contacting and communicating with the crankshaft.
Many conventional lubricating systems also utilize oil filtration modules attached to the exterior of the air compressor. Such systems, as described in U.S. Pat. No. 5,183,134 to Kuc, seek to address efficient removal of wear inducing particulate matter from oils while at the same time providing easy access to the filter for inspection and maintenance. However, this arrangement does not allow for easy maintenance and inspection of other system components such as oil fill, oil pressure, and oil level, especially in those instances where a locomotive does not provide access to both sides of the air compressor.
Another problem with conventional compressor lubrication systems is that despite having means for relieving fluid pressure when safe operational limits are exceeded, such conventional systems do not provide dynamic closed-loop regulation of the oil system pressure. Conventional compressor lubrication systems provide for excess fluid pressure to be released externally from the air compressor, but fail to provide an arrangement that allows the excess fluid pressure to be used in a closed-loop configuration within the air compressor.